Now it is bright as 10.0 mag (Dec. 5, Juan Jose Gonzalez). It is observable all night in the Northern Hemisphere. In the Northern Hemisphere, it stays observable in excellent condition for a long time. In the Southern Hemisphere, it will never be observable again after this. It started fading before the peirhelion passage.

Now it is very bright as 11.7 mag (Dec. 8, Katsumi Yoshimoto). It will approach to Earth down to 0.07 a.u. in mid December, and it will brighten up to 10 mag. In the Northern Hemisphere, it stays observable in excellent condition until mid December. In the Southern Hemisphere, it stays low.

Now it is 11.2 mag (Dec. 4, Thomas Lehmann). It stays 11 mag until December. It is observable in good condition in the Northern Hemisphere. It locates very low for a long time in the Southern Hemisphere.

Now it is 11.2 mag (Dec. 7, Chris Wyatt). It will stay bright as 11 mag for a long time from winter to next spring. In the Southern Hemisphere, it stays observable in good condition until next February. In the Northern Hemispehre, it stays observable for a long time after this until the comet fades out.

It brightened up to 7.1 mag from May to June (June 21, Juan Jose Gonzalez). Now it is fading. It has already faded down to 13.5 mag (Dec. 7, Chris Wyatt). In the Southern Hemisphere, it stays observable for a long time after this. It will never be observable again in the Northern Hemisphere.

Now it is 14.9 mag (Dec. 1, Katsumi Yoshimoto). It will approach to Earth down to 0.2 a.u., and to Sun down to 0.6 a.u., and it is expected to brighten up to 10-11 mag from winter to spring. In the Northern Hemisphre, it stays observable in good condition until January, but it will be extremely low after that. In the Southern Hemisphere, it is not observable from January to mid March, but it stays observable in good condition except for that period.

It brightened very rapidly from July to August. Now it is very bright as 14.2 mag (Nov. 8, Chris Wyatt). It is observable in excellent condition in the Southern Hemisphere. It stays low for a while in the Northern Hemisphere.

Now it is 14.0 mag (Nov. 28, Toshihiko Ikemura, Hirohisa Sato). It is expected to brighten up to 12 mag from 2018 to 2019. In the Northern Hemisphere, it stays observable in good condition while the comet will be brightening gradually. In the Southern Hemisphere, it is not observable until 2018 October.

It will brighten very rapidly, and brighten up to 11 mag from January to February. In the Northern Hemisphere, it stays observable for a long time in the evening sky. In the Southern Hemisphere, it locates extremely low at the highlight.

Brian Skiff found a bright outburst on Dec. 7. Now it is bright as 13.5 mag (Dec. 7, Richard Miles). This is the 4th outburst following those in January 2006, May 2011 and August 2016. It stays observable in good condition for a while.

Now it is 13.7 mag (Nov. 14, Gabor Santa). It is expected to brighten up to 10 mag in summer in 2018. In the Northern Hemisphere, it stays observable until 2018 summer while the comet will be brightening. However, it will be extremely low from December to January. In the Southern Hemisphere, it is hardly observable in 2017, but it will be observable in good condition in 2018.

Now it is 14.2 mag (Nov. 14, Artyom Novichonok). It will be observable at 14 mag for a long time from 2017 to 2018. In the Southern Hemisphere, it will be hardly observable after this. It will be extremely low from November to December in the Northern Hemisphere.

It brightened up to 10 mag from spring to summer. Now it is fading. It has already faded down to 14.8 mag (Dec. 4, Thomas Lehmann). It is observable in excellent condition in the Southern Hemisphere. It locates low in the Northern Hemisphere.

Now it is 14.7 mag (Dec. 7, Chris Wyatt). It stays 15 mag until winter. In the Southern Hemisphere, it stays observable in excellent condition until spring in 2018. In the Northern Hemisphere, it stays unobservable until 2018.

Now it is 14.8 mag (Nov. 14, Gabor Santa). In the Northern Hemisphere, it stays 15 mag until winter, and it is observable in excellent condition. It is not observable at all after this in the Southern Hemisphere.

Now it is 15.6 mag (Nov. 22, Sandor Szabo). It stays observable at 16 mag for a long time until summer in 2018. It is observable in good condition in the Northern Hemisphere in 2017, and in the Southern Hemisphere in 2018.

It brightened rapidly. Now it is bright as 14.8 mag (Nov. 22, Sandor Szabo). Return of a new periodic comet which brightened up to 13 mag in 2004. It is be observable in excellent condition in autumn. It continues brightening even after the perihelion passage.

It brightened up to 6.2 mag in April (Apr. 7, Juan Jose Gonzalez). Now it is fading rapidly. It has already faded down to 13.5 mag (Nov. 14, Sandor Szabo). It stays observable for a long time after this.

Now it is 16.3 mag (Nov. 15, Toshihiko Ikemura, Hirohisa Sato). It stays 16 mag for a long time from 2017 to 2018. It is observable in excellent condition in the Northern Hemisphere. It locates very low in the Southern Hemisphere.

Now it is 16.9 mag (Nov. 20, Toshihiko Ikemura, Hirohisa Sato). It will brighten up to 9 mag in 2018 summer. However, it is hardly observable when it is bright. In the Northern Hemisphere, it is observable only until March when it brightens up to 14 mag. In the Southern Hemisphere, it is observable from July to September in 2018, but it locates in extremely low.

Now it is 16.9 mag (Nov. 23, Toshihiko Ikemura, Hirohisa Sato). In the Northern Hemisphere, it will be observable at 17 mag in excellent condition from autumn to winter. It locates low in the Southern Hemisphere.

Now it is 16.7 mag (Nov. 15, Toshihiko Ikemura, Hirohisa Sato). It will pass the perihelion in 2019. However, it has not been brightening since the discovery in 2010. It is observable in good conditioin in the Northern Hemisphere. It is not observable for a long time in the Southern Hemisphere.

Now it is 16.6 mag (Sept. 16, P. Camilleri, H. Williams). It will brighten up to 14 mag from autumn to winter in 2018, and it will be observable in excellent condition in the Northern Hemisphere. In 2017, it is observable at 17 mag in excellent condition in the Southern Hemisphere.

Possible first interstellar object in the history. It approached to Sun down to 0.25 a.u. on Sept. 9. Now it is fading rapidly. It was 19.0 mag in mid October (Oct. 14, Catalina Sky Survey). But it has already fade down to 24.3 mag (Nov. 17, W. H. Ryan, E. V. Ryan).